1. Field of the Invention
The present invention relates to processes and compositions for the manufacture of air, heater and air conditioning ducts. More particularly, the present invention relates to process and compositions for the manufacture of air, heater and air conditioning ducts, including bellows-type or convoluted ducts. The present invention also relates to processes and compositions for the manufacture of vehicle-associated air, heater and air conditioning ducts.
2. Prior Art
Air ducts, such as those used with vehicular heaters, and air conditioning systems are well known. Generally, such ducts or conduits comprise a wire support structure having a cloth or rubberized material secured thereto and enveloping the same. The cost of manufacturing such products is quite expensive with respect not only to materials but with respect to labor also. In order to manufacture the ducts it is necessary first to form the wire structure. Then the enveloping material must be secured thereto. Thus, the prior art has sought means and methods to alleviate this problem. See, inter alia, U.S. Pat. Nos. 3,313,319 and 2,728,356. These patents teach the formation of ducts or conduits from various synthetic products, such as polyethylene, polytrichloroethylene and the like. However, this solution has not been fully successful.
There remains the problem of manufacturing such articles to meet all climatic conditions, both hot and cold weather, while still maintaining their structural integrity. Furthermore, such articles must be able to withstand the force vectors which are created by velocities of air currents, which can also be at elevated temperatures, passing therethrough. It must be appreciated that a major advance in the art would be provided by an air duct of reduced cost and excellent thermal and structural stability.